Success and failure rates of 9 mm or shorter implants in the replacement of missing maxillary molars when restored with individual crowns: Preliminary results 0 to 84 months in function. A retrospective study

Background: The ability to utilize shorter implants in the reconstruction of the posterior maxilla would, theoretically, simplify therapy by lessening the need for augmentation surgery. The purpose of this retrospective study was to assess the success and failure rates of : 9 mm or shorter implants in the maxillary posterior regions restored with individual crowns. Methods: A total of 979 implants were placed in maxillary molar positions and restored with individual crowns. The implants were followed in function for up to 84 months. The results are discussed in terms of clinical applicability and indications for use. Results: The cumulative success rates in function were 94.5% for implants in the maxillary first molar positions and 98.7% for implants in the maxillary second molar positions, yielding an overall cumulative success rate of 95.1%, in function for up to 84 months. Conclusion: These findings suggest that non-countersunk implants of 7 to 9 mm in length may be successfully restored with single crowns in the maxillary molar region.